My invention relates to the structure and operation of a previously installed mechanical door lock which is upgraded with override electromagnetic lock components. In particular my invention relates to electromagnetic locking components and deadbolt (or hook bolt), all of which are enclosed within a hollow doorframe casing. However, my new lock is also adaptable to other doors or other closed containers or spaces which require a fail-secure electronic locking component which overrides previously installed mechanical locking components.
In the preferred embodiment, my integrated lock is best suited to narrow stile doors, such as doors generally comprised of a glass core with a surrounding hollow metal frame. The lateral longitudinal plate comprises a longitudinal surface from which the bar or bolt extends through a rectangular opening. In addition to this lateral longitudinal plate, my invention comprises anterior and posterior plates. A longitudinal edge of each anterior or posterior plate is attached to a corresponding edge of the lateral longitudinal plate and forms a three-sided enclosure with two right angles.
In the preferred embodiment of my invention, the mechanical deadbolt operates from a fully extended position to a fully retracted position within the rectangular opening through an arc of 90 degrees. The operating mechanism comprises a rocking lever mounted perpendicular to the deadbolt. The rocking lever physically engages the deadbolt through pins and slot connections.
The cylindrical lock in my preferred embodiment is of the conventional type operable by a key. This lock cylinder carries a cylindrical extended shaft in which the key is inserted. The cylindrical extended shaft comprises a rotating cam member that attaches to the extended shaft's interior end with two screws. The operator rotates this cylindrical extended shaft clockwise or counterclockwise by turning the key within it.
The inner end of the deadbolt is bifurcated, and the legs formed therefrom contain arcuate shaped apertures. The legs are pivotally attached to the lower end of a rocking lever by a pivot pin which extends though the lower portion of the rocking lever. The rocking lever is physically positioned above the deadbolt and is adjacent to the lock cylinder.
Two opposing roller cams are mounted on a sleeve, and the sleeve ends move in a limited manner within curved apertures within each anterior or posterior plate. Each of these apertures in each plate is arcuate and at its ends each has upwardly extending grooves. In operating the rocking lever, there is engagement of each opposing roller cam within each anterior and posterior plate and within the lever, by which each roller cam moves within the limits of a keyhole shaped aperture within the rocking lever.
My invention does not change the function, purpose or intent of the prior art mechanical locking device: to secure the door against physical tampering. Instead, my new door lock provides a second level of security in addition to the conventional mechanical key method. With my new electromagnetic lock, a person (i) initially must have a card, fob or a correct code to enter onto a key pad, to (ii) subsequently release the keyed cylinder shaft for rotation.
A second level of security is important when business owners confront certain days and/or hours in which it is difficult, impossible or very expensive for a locksmith to make a service call and re-key the locks. In contrast, with my invention the business owner easily recodes an access control device without requiring a professional locksmith.
Installation of my invention alleviates this problem by addition of the following to the existing mechanical deadbolt or hook bolt:
1) solenoid or other magnetic field generating device;
2) a solenoid cylindrical casing which connects the solenoid to a prior mechanical installed lock component;
3) a hollow stem inserted in the cavity of the solenoid cylindrical casing with a locking portion attached thereto; and
4) a small spring between the hollow stem and hollow cavity within the solenoid cylindrical casing,
The access control portion of the electronic portion of my invention includes:
1) an exterior door or frame mounted reader (i.e, proximity, magnetic swipe, biometrics hand, finger or eye reader, bar code reader, Dallas touch chip reader, digital push button keypad reader, etc.);
2) a door controller device which contains a circuit board, including but limited to memory e-prompt components, relay battery and wire connectors;
3) a transformer power supply and the appropriate wire connecting components.
When combined with stand alone or audit controlled computer based systems, such an access control system enables the business owner to create a report showing authorized employee access with the appropriate time and date. The door controller device identifies, via the reader, the previous entered information as to who can or cannot gain access. The door controller device can also electronically add or delete authorized users. The authorized person inserts his key, rotates the extendible shaft or pivot pin, and gains access only after the card access system has enabled the authorized person to gain access.
When the door control time has expired, usually about five or six seconds) the power rapidly ceases, thereby preventing the key from turning within the exterior cylinder lock. To comply with relevant fire codes, the interior keyed cylinder lock (or non-keyed thumb turn) on the interior surface of the doorframe cannot be controlled by the cam retaining locking bar. The absence of cam retaining locking bar control thereby allows persons unrestricted egress from a room or building interior in emergencies.
The process of installation of the electromagnetic component is another feature of my invention. My novel process of installation provides a significant economic advantage for, but not exclusively, commercial office space or privately owned businesses within large buildings. In these buildings, locks can be simultaneously upgraded with electronic security components without replacement or modification of a door component.
In addition, with my invention no new apertures are cut into the hollow metal doorframe casing to accommodate more expensive magnetic lock or electric strike hardware. Using my process, the operator removes the lateral, anterior and posterior plates and inserts a solenoid and associated components within the hollow metal doorframe casing.
The prior art discloses numerous mechanical locks cooperating with electrical components. However, these electrical components are not designed for installation after the mechanical locking component is installed within the doorframe. U.S. Pat. No. 5,561,997 (Milman) discloses a cylindrical barrel type lock wherein rotation of the barrel is prevented by one or more armatures. These armatures in turn are actuated by an electromagnet.
U.S. Pat. No. 5,542,274 (Thordmark et al.) discloses a cylinder lock comprising a key operated cylinder plug. A latching element is located near the boundary surface between the lock cylinder and a plug. There is also an electrical blocking element which moves between a release position and a blocking position. U.S. Pat. No. 3,733,861 (Lester) discloses an early electronic recognition door lock. Lester also comprises a solenoid which is activated to withdraw an abutment member from a laterally sliding door bolt mechanism. U.S. Pat. No. 5,469,727 (Spahn et al.) discloses an electronic lock cylinder comprising a housing with a cylindrical core.
Electronic control circuits are coupled inductively via coils for transmission of coding information. There is separate assembly of the mechanical components and of the electronic components of the lock cylinder. Spahn's electronic lock cylinder differs in part from my pending invention in that there is no disclosure of a process which integrates the electronic and mechanical components after prior installation of the mechanical component within a door frame.
U.S. Pat. No. 5,136,870 (Gartner et al.) discloses an electronic door lock. A digitally operated code input pad assembly enters a first code and a second code to open a second lock mechanism with the door spring bolt. These locks are adaptable for replacement of an ordinary deadbolt lock mechanism. However, Gartner's lock does not provide for subsequent installation within a doorframe of only the electronic lock component at a minimum cost and destruction of the doorframe.
Other early locks have even less technically in common with respect to upgrades with my present invention. U.S. Pat. No. 4,916,927 (O'Connell et al.) discloses a lock in which a solenoid can move an obstructing element entire into a recess. The presence or absence of the solenoid's magnetic field prevents turning of the shaft within a key cylinder. However, O'Connell's device must be installed with all its components simultaneously into a doorframe.
U.S. Pat. No. 4,831,851 (Larson) discloses a lock mechanism comprising a mechanical combination lock and an electronic lock. The mechanical combination lock serves as a fail-safe entry in case of failure of the electronic lock. However, this lock is specifically applicable to small safe deposit boxes.
U.S. Pat. No. 4,745,784 (Gartner) discloses an electronic dial combination lock. U.S. Pat. No. 3,748,878 (Balzano et al.), discloses an electrically controlled manual unit for a door lock. This lock also comprises a cylinder which contains a solenoid. The solenoid is energized to engage a clutch for rotation of the knob and connecting cam. Balzon's system, however, does not comprise an electronic component which can be installed subsequent to the mechanical lock unit within a door frame.
U.S. Pat. No. 5,636,880 (Miller)discloses an electronic lock which comprises a dead latch assembly for narrow stile locks, but not necessarily a hollow metal door frame casing comprising a door.
No distinct solenoid housing, cylindrical solenoid casing, or cam retaining locking bar is disclosed as described by Applicant, infra.
Furthermore, the operation of Miller's lock differs from that of Applicant's as it does not comprise a free standing electronically controlled obstructing component. In contrast, Applicant's electronically controlled element (cam retaining locking bar with attached stem and spring) rises within a magnetic field, and falls vertically in zero magnetic field.
My locking devise integrates previously installed mechanical locks with electronically controlled components which override entry-authorizing mechanical lock components. In particular, my new electromagnetic lock easily replaces a previously installed mechanical deadbolt with an improved electromechanically controlled deadbolt or hookbolt. My new lock is especially suited for small business properties with numerous narrow stile deadbolts, but who require a “second level” of electronic security. My lock installation also reduces costs and installation time from conventional locks with access control.